Grinding tool



Oct. 4, 1932.

L. M. BUTLER 1,881,042

GRINDING TOOL Filed Sept. 19, 1929 2 Sheets-Sheet 1 a I I W 24 *k" Z5 1 1s 23 1 l /7 us 4 I I I m I Oct. 4, 1932.

| M. BUTLER 1,881,042

GR INDING TOOL Filed Sept. 19. .1929 2 Sheets-Sheet 2 Patented Oct. 4,v 1932 UNITED STATES PATENTE OFFICE LEO BUTLER, 0F SEATTLE, WASHINGTON, ASSIGNOR TO BOEING AIRPLANE COMPANY,

OF SEATTLE, WASHINGTON GRINDING TOOL This invention relatesto improvements in grinding tools and more especially to a grinding tool adapted. for'grinding opera-' 'tions in the construction of aircraft.

It is a matter of great difiiculty to build airplane fuselages so exactlythat all parts will occupy precisely the positions and planes which it is intended they shouldoccupy; The engine ring, for instance, may be slightly inclined 'relative'to the longitudinal axis of the fuselage, yet to allow the engine to be mounted thereon in such manner that its axis is inclined,even slightly, relative to the axis of the" fuselage, would seriously impair the performance of-the airplane and shorten its life,if it didnot render it unsuitable for flying. It is necessary to secure bosses on the engine ring, projecting. forwardly, to 'whichthe engine is secured, and

. which afford a means for-seating the engine with its axis exactly in linewith orparallel to the longitudinal axis of the fuselage. The ends of such bosses must be ground off or otherwise removed in a'plane exactly at right angles to this axis, notwithstanding any dew parture of the engine ring from such a plane.

It isthe principal object of thisinvention to provide a device of this character which can be mounted upon the forward end of an air- Vm plane fuselage, and moved about acircle to grind away all such bosses evenly, to form a seat for the engine that will be at right angles to the longitudinal axisof the airplane. 1 I

"Sincea rotary grinder which merely moves 1 in one path, whether about a'circle or radially, or insome other single direction, will leave I a concave surface, not a flat one, it is necessary to give such a grinder, as it moves over .40: each one ofthe bosses, a compound move- .ment. Hence, another object of the invention is to advance the grinder so that its line of contact with the work. will in effect move radially as well as circularly withrespect' to I the work.

These and other objects will appear as'my invention is more fully hereinafter described in the following specification, illustrated in the accompanying drawings and finally pointed out in the appended claims.

In the drawings: 1

Figure 1 is a top plan view of an airplane fuselage showing my improved form of grirlilding-tool in operative engagement therewit i I Figure 2 is aside elevation of Figure 1.

Figure 3 is a front view of Figure 2, showing in dotted lines the operative range of the grinder.

Figure 4: is an enlarged View of a hand wheel.

Figure 5 is anenlarged detail viewof an engaging means for the hand wheel with one of the gears.

Referring now more particularly to the drawings:

Reference numeral 1 indicates the forward end of an airplane fuselage to which is secured the usual engine mount for a radial air cooled engine. The engine mount is in the form of an apertured ring 2 havingbosses, 3 around the apertures; The engine bolts pass through the apertures and are provided with nuts on the inner side of the ring. As the nuts are advanced on the threads of the bolts, the engine is of course drawn tight against the bosses and it is therefore necessary that the length of the bosses be such,

, without respect to the amount of their proscrews are advanced on their threads.

By suchmeans the plane of rotation of the working faceof a grinding tool 13, mounted for rotation upon'a base established by the posltion of the spokes 7 as will appear hereafter, canbe adjusted to coincide with a plane at right angles to the'long'itudinal axis of the fuselage, and. is notcontrolledby the planeof the ring 2. If the ring .2 is canted "relative to a plane perpendicular to the longitudinal axis of the fuselage, the-screws 7B will so adjust thespokes 7 (of which "there are at least three) that this canting will be QQmPen' ate for, and thewo ng iac 9f the, grinder will alwayslie only in atrue: perpendicular plane.

For supporting" the. spokes 7 and their re;

lated parts in positionagainst the ring 2 after adjustment into such a; perpendicular I plane, a disc.9 is provided. .Extending radially from the disc a area plurality of arms "'10 which are adapted to engage'with the structuralparts' of the fuselage as shown inFiguresland'Q, An adjusting screw 11; isthreadedIy mounted through the disc9' and is adapted to exert pressure against'the hub The hub islhollow to riigidly support ashaft 8. I f i 7 Rotatably mounted on the shaft Sis "a platform 11A. .An electric motor 12, driving a grinding wheel 18, is slidably niountedfto the top of the platform, and can be "traversed Y thereon means ota threadedi'shaft 14 which is provided at itsouter end with a'ha nd' Wh-eel'1'5 for convenience in moving the motor back and forth -across'the platformg The grinding wheel is provided with'a guard 15A "whichis bolted to "them'otor. j Anarm 16 extends downward y from. t e 'a rml and'calrries a counterweight 17. The platform is also slidable axially of. the "shaft 8 and "can beset up to cause the grinderto takeoff morematerial fromtheen'dsof the bossesafter it'has ground down to the limit of a given setting, by means'of a 'threaded shaft 17 A and hand Wheel 1713. 'Fixed to theshaftS is a gear'18 intermeshing with a gearftrainyconsisting of gears 19', 20, 2 1,- 22, 23,- and 24', and a ratchet wheel 25. The wheels 24: and 25 are secured together by means of-screws 26 but can rotate independently'of the hand wheel which is keyed or otherwise fastened to the shaft 14. Mountedon one side of the hand wheel 15 and located,

" car bearing aeaiwhich is adaptedtoslidablyj directly overtheratchet wheel 25 is a verti and pi-votal'ly support-a'pawl 27.' =Arpin 28 lat all times. In the dotted line position is carried-by the pawl and a spring 29 is interposed between the ,pin and the vertical bearing to keep the pawl under spring tension shown in, Figure 5 thei'pawlis clea'r of'the ratchet wheel 25 and the'hand wheel-15 is free to be rotated;forgmanual' "adjustment "inde-' pendentlyof the gearstrain; In the full line L resta t positio'n'the pawl is engaged with the teeth;

and when so engaged the hand; wheel will rotatejwith the ratchet wheel 25 when the platform is swung in one direction, and on the back swing the pawl will ride over the teeth due to the slant on the back side of the pawl, as shown in Figure 5.

-. At the outset of a grinding operation, the

device havingbeen set up so that the workmg face of the rotary-grinder l3 swings in a plane perpendicular to -the longitudinal axis of the fuselage, and the motor a nd'grinder being at one limit of their traversing movement (the inner limit fo'r instanceiwhere the work-ing face ofthe grinder is the least radial distance from theshaft '8), thegrinder is brought into contact withthe highest of the bosses 3. It bitesinto the inner facethereof,

and as-the end-of this boss wears away, the

i swinging the motor and' grin'der, and its platform 11A and the counterweight 17, from side to side, as is indicated by the dotted lines in Figure .3. The gear wheel 18 being a secured "to the shaft 8 of course does not rotate but the geargtrain intermeshing with it is put into motion, and the-rati'o-of the gear-' ing is'suchthatduringthe swing of the mo-' tor, approximately to .the limits indicated by the dotted lines of Figure 3f, theiiratchet a wheel 25 and theihandrwhe'el '15; connected" with itareicausedto rotate by means of'the' pawl 27 through a'part ofafrevolution, sufii cient to-advance the grinder for further grinding? Thisturning of-the hand wheel imparts rotary movement ;.-to. the shaft 14 with a resultant "advancement of-the motor on'the-platform. As the motor is advanced the grinding wheel covers more of the boss until finally theentire'surfaceof the'bos's is ground away as a plane:

After the 'highest boss has'jjbeen ground away to thelevel of thene'xt higher boss or bo's'ses5 "the :platitorm; 11A" and its motor 12 and grinder 13 are'set up by the scr'ewl'r'A, andthe grinder may now contact with several bosses of like height; Several such bosses may be ground at one time-without danger of 'breakingthe grinder and the-motor and grinder can be swung a greater distance, having regard t 'the fact that' the amount; of traverse is controlled by the amount ot'swing, andthat the grinder must not be a'dvancedtoo fast, to take ofltoo much;

material 'at 'each fbite) If ithe traversing movement of'the grinder isto be from-the insideftow'ards the outside-, thehand wheel 7 15 is turned to bringthemotor and grinderinside (to the left, as seen in Figure 3), and

the swinging operation described is repeated. The grinder rapidly and repeatedly contacts now with several bosses of like height, and in effect moves outward gradually across them, as the traversing movement efiected by the screw 14 increases the effective radial distance of the grinders working face from the axis of the shaft 8.

Finally all the bosses are brought down to the same level, the top of each one plane,

' and each top lying precisely in a single plane which is perpendicular to the longitudinal axis of the fuselage, though some may project farther from the engine ring 2 than others. The grinding may stop here, or if for any reason it is desired to grind farther, the tool is set up with the screw'17A, and

. the entire operation repeated.

While I have shown a particular form of embodiment of my invention, I amaware that many minor changes therein will readily suggest themselves to others skilled in the art without departingfrom the spirit and scope of my invention. Having thus described my invention, what I claim as new and desire to protect by Letters Patent is 2- 1. In a tool for performinga grinding operation of the type described, the combination of a frame, a platform swingably mounted wlth respect to said frame, a motor driven grinding wheel mounted for traversing movement on the platform, a screw for movingsaid grinding wheel with respect to the platform, I

a gear train interconnecting the screw with the frame whereby oscillatorymovement of the-platform will cause the grinding wheel to feed toward the work to be dealt with.

2. In a device of the class described, the combination of a frame adapted to be mounted to the fuselage of an airplane, a shaft extending outwardly from said frame, a platform rotatably mounted on said shaft, a motor driven grinder .mounted on said plat-form and a screw for adjusting said grinder transversely of the platform, a gear wheel stationary with said shaft, a gear train interconnecting with said stationary gear to rotate and advance the said .screw upon oscillating the platform.

3. In a grinding tool for the purpose described, a support, means for supporting the same from a fuselage, means for adjusting the same with reference to a plane perpendicular to thelongitudinal axis of such fuselage, a V

grinder, means supporting said grinder from said support for movement of its working face in a given plane, which plane by the ad justing means referred to can be made to coincide with a sel'ectedplane at right angles to the longitudinal axis of the fuselage.

4. A grinding tool as in claim 3, the grinder support including means to move the grinder in two directions in its plane of movement,

to traverse the working face thereof in such plane.

5. A grinding tool as in claim 3, the grinder support including a platform oscillatable about an axis parallel to the longitudinal axis of the fuselage, and a slide upon which the grinder is mounted, and which is traversable upon said platform to alter the radial distance from the working face of the grinder to the axis of oscillation.

- 6. A grinding tool as in claim 3, the grinder support including a platform oscillatable about an axis parallel to the longitudinal axis of the fuselage, and a slide upon which the grinder is mounted, and which is traversable upon said platform to alter the radial distance from the working face of the grinder to the axis of oscillation, and means operable by the oscillatory movement for traversing said slide relative to the platform.

7. In a grinding tool for the purpose described, a supporting shaft, means to adjust the same with reference to the longitudinal axis of a fuselage, a grinder, a platform carrying said grinder and oscillatably supported upon said shaft to swing the grinder with its heretofore mentioned, nearer to or farther from the axis of said shaft.

8. A grinding tool as in claim 7, the grinder being movable along a chord of its arc of swing, from an outward limiting position inwardly towards a radius, or the reverse.

9. A grinding tool as in claim 7, and means including a ratchet drive, and operable by oscillatory movement of the platform, to automatically traverse the grinder.

10. A grinding tool as in claim 7, a gear fixed to the supporting shaft, a screw journaled in the platform and threaded in the immediate grinder support to traverse the same, and a gear train and ratchet means operatively connecting the gear upon the shaft and said screw to advance the same as the platform is oscillated.

11. A grinding tool as in claim 7 and mean upon the shaft for advancing the platform and associated parts axially of the said shaft.

In testimony whereof I affix my signature.

- LEO M. BUTLER. 

